In a luxurious Rube Goldberg method of shipbuilding, Maison Krug Italy's master sommelier Michela Cimatoribus popped the cork from a magnum of Krug Grande Cuvée Champagne, which signaled the drop of confetti and the start of a laser cutting the first piece of steel for the 750-passenger ship.

"This piece of steel will be used as the foundation for an opulent and luxurious owner's suite that will not only rival, but surmount anything like it in the marketplace today," said Kunal S. Kamlani, president of Regent Seven Seas Cruises. "We billed this ship as, 'It will be the most luxurious ship ever built.' Of course, when you come out with such a bold acclamation, you would expect consumer as well as guest expectations to be running high, and rightfully so. We fully intend to exceed those expectations."

According to the line, the 54,000-ton Explorer will feature the highest space ratios and staff-to-guest ratios in the cruise industry. It will be an all-suite ship, just like the Seven Seas Mariner and Seven Seas Voyager. The Explorer will have 369 suites ranging in size from 300 to 1,500 square feet. It will become the fourth and also the largest ship in the fleet and will increase the line's capacity by 40 percent, Kamlani said.

The Seven Seas Explorer is due summer 2016.

"We're one step closer to fulfilling our dream of building the most luxurious ship in the world and giving our guests another exciting option to explore inspired global destinations with our special brand of all-inclusive luxury," said Kamlani. "Seven Seas Explorer will surpass the current standard in luxury cruising, offering a new level of grandeur throughout the ship from its lavish suites to its elegant public spaces and gourmet restaurants."

It's the first time the line has partnered with Fincantieri. The line hasn't had a new ship introduced to the market since 2003. Fincantieri did construct Regent Seven Seas' sister line Oceania's newest ships though, the Marina in 2011 and Riviera in 2012.

"We are extremely excited to welcome a new partner in Regent Seven Seas Cruises and to start construction of this brilliant new ship," said Fincantieri CEO Giuseppe Bono. "As a global leader in cruise ship construction, we've built some of the finest ships at sea. Building the most luxurious ship ever built is quite a challenge, but with our craftsmanship and experience building luxury ships we feel that Seven Seas Explorer will become the definition of excellence."

Reservations for the inaugural season can be made starting in early 2015.

The Royal Caribbean Quantum of the Seas was built at the Meyer Werft shipyards and delivered in October 2014. It's the first of two ships that have been part of the line's Project Sunshine. The sister ship Anthem of the Seas is due in spring 2015. Read about ship details